Pneumatic product-on-demand delivery systems have been used on agricultural seeding machines to automatically direct seed from a main seed hopper to a plurality of individual planting units. Each of the individual planting units has an auxiliary seed hopper for receiving the seed, a seed meter for metering the seed from the auxiliary seed hopper and a furrow opener for forming a planting furrow into which the metered seed is deposited. A fan is used to create pressurized air that forms an air stream on which the seed is taken to the planting units. These systems automatically replenish the auxiliary hoppers as needed.
The commercially available seed on demand delivery systems typically require a large fan to create the air stream. The large fan is required because of the pressure losses in the pneumatic system caused by abrupt changes in direction by the air stream in the main hopper.
Another system is described in U.S. Pat. No. 6,609,468, herein incorporated by reference. According to this patent, a product-on-demand delivery system is configured wherein the air stream passing through the main hopper is not subjected to the abrupt changes in direction.
The product-on-demand delivery system of the patent comprises a frame having a main hopper and an application unit. An air pump directs pressurized air to a manifold where the pressurized air is distributed to a plurality of air supply hoses. The air supply hoses are coupled to air inlets located on the bottom of the main hopper. Opposite the air inlets are corresponding product outlets for receiving the air streams with product, such as seed, entrained in the air stream. The product outlets are coupled to product supply hoses that are in turn coupled to auxiliary hoppers located on the application units. The bottom of the main hopper is concave and has outwardly diverging side walls. The air inlet is downwardly angled relative to the bottom and the product outlet is upwardly angled relative to the bottom.
Peaked baffles are located above corresponding air inlets and outlets so that product “puddles” form beneath the baffles. Gaps are formed between adjacent baffles so that product from the main hopper can flow into the product puddles.
The product-on-demand delivery system of this patent can be used to supply seed from a main seed hopper to auxiliary seed hoppers located on a planting unit. The planting unit includes auxiliary seed hoppers that each supply seed to a respective seed meter, each of which directs metered seed to a planting furrow formed by a furrow opener.
Typically, seed air delivery systems use a common fan to deliver air to the complete planter. In a typical air delivery system for a bulk seed planter that supplies a plurality of application units, there is required a minimum level of air pressure to deliver the seed to the furthest row application unit from the main hopper or tank. The fan is turned up to that level to ensure adequate delivery of seed to all application units of the machine. Due to this fact, however, the closest row units that are fed by shorter seed delivery hoses can be subjected to greater flow rates or higher pressures. It is difficult to prevent the closest row units from being overfilled.
The present inventors have recognized that it would be desirable to provide a product-on-demand delivery system that provides product to plural application units and supplies a correct amount of product from the main hopper to both distant application units and near application units. The present inventors have recognized that it would be desirable to provide a product-on-demand delivery system that delivers product, such as seed, from main hoppers to application units that reduced the probability of overfilling and plugging.
The present inventors have recognized that it would be desirable to provide a product-on-demand delivery system that could be used to simultaneously apply different products to different groups of rows in the field. The different products could be different kinds of seed varieties, treatments, shapes, sizes, etc., or different crops.